From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42640) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gPmMB-00038i-Jg for qemu-devel@nongnu.org; Thu, 22 Nov 2018 05:37:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gPmM9-0004Nn-01 for qemu-devel@nongnu.org; Thu, 22 Nov 2018 05:37:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51510) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gPmM8-0004MD-Qj for qemu-devel@nongnu.org; Thu, 22 Nov 2018 05:37:08 -0500 From: Igor Mammedov Date: Thu, 22 Nov 2018 11:29:33 +0100 Message-Id: <1542882574-109418-2-git-send-email-imammedo@redhat.com> In-Reply-To: <1542882574-109418-1-git-send-email-imammedo@redhat.com> References: <1542882574-109418-1-git-send-email-imammedo@redhat.com> Subject: [Qemu-devel] [PATCH 1/2] pc: acpi: use correct RSDT length for checksum List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: sameo@linux.intel.com, mst@redhat.com, drjones@redhat.com, peter.maydell@linaro.org AcpiRsdpDescriptor describes revision 2 RSDP table so using sizeof(*rsdp) for checksum calculation isn't correct since we are adding extra 16 bytes. But acpi_data_push() zeroes out table, so just by luck we are summing up exta zeros which still yelds correct checksum. Fix it up by explicitly stating table size instead of using pointer arithmetics on stucture. PS: Extra 16 bytes are still wasted, but droping them will break migration for machines older than 2.3 due to size mismatch, for 2.3 and older it's not an issue since they are using resizable memory regions (a1666142d) for ACPI blobs. So keep wasting memory to avoid breaking old machines. Fixes: 72c194f7e (i386: ACPI table generation code from seabios) Signed-off-by: Igor Mammedov --- there is no changes to the current RSDP content caused by this patch --- hw/i386/acpi-build.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 236a20e..131c565 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -2567,7 +2567,7 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offset) /* Checksum to be filled by Guest linker */ bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE, - (char *)rsdp - rsdp_table->data, sizeof *rsdp, + (char *)rsdp - rsdp_table->data, 20 /* ACPI rev 1.0 RSDP size */, (char *)&rsdp->checksum - rsdp_table->data); return rsdp_table; -- 2.7.4